In a known laminated insulator of this type (EP-0 333 145), it is deemed undesirable that under conditions of intense light irradiation and simultaneous high exterior temperatures, e.g., as encountered in the summer, the proportion of incident light energy converted to heat within the system and up to the building wall is high, and that accordingly, the temperature in the interior of the building is increased.
It is known (DE-A-35 22 078) to employ a liquid material to control light permeability as a function of temperature, rendered practicable by enclosing the liquid in a transparent enclosure. The material reversibly changes its light permeability with temperature. The transparent body serving as an enclosure element (or elements) for the liquid may be, e.g., a laminated plate, or a plastic sandwich sheet or plate. Automatic light-attenuation means are provided thereby. The outer dimensions of the said enclosure element determine the size of the unit, i.e., the thickness of the flat body which results. The problem of the shading of glass surfaces can be solved with the use of such bodies, i.e., an effective, maximally automatically operating shading means is produced which enables utilization of the heating capability of sunlight in the winter but prevents excessive heating from sunlight in the summer. Further, one can dispense with the otherwise commonly used but costly window shades employed to control light penetration.
A disadvantage of the known solutions from the standpoint of building technology has turned out to be that the bodies produced from the conventional units are bulky and unwieldy. Thus, construction with such pre-manufactured transparent bodies is difficult and expensive to perform, because precise architectural planning is required in order to install the bodies in precise positions relative to each other and the other structural features of the building under construction. Moreover, the plates with their smooth outer surfaces lend a distinct appearance to the finished building which is generally unattractive. In addition, there is the functional drawback that light passes through the plates and is absorbed at some distance from them. Consequently, the plates allow infrared (IR) radiation to pass, which have high heating properties, and in particular it passes until the regions behind the plates are overheated before the heat conducts back to the plates and brings about the needed reduction of the transparency of the plates.